Effects of modified-release fampridine on upper limb impairment in patients with Multiple Sclerosis

Sustained-release oral dalfampridine appears to have no impact on upper extremity function in people with multiple sclerosis: a randomized controlled trial

Background

Upper limb dysfunction is common in people with multiple sclerosis (pwMS), significantly affecting daily activities and quality of life. While dalfampridine has shown efficacy in improving gait in pwMS, its impact on upper extremity function remains unclear.

Objectives

To evaluate the effect of sustained-release oral dalfampridine on upper extremity function in pwMS.

Design

A randomized, placebo-controlled trial.

Methods

In all, 30 pwMS were randomized to receive either dalfampridine (10 mg twice daily) or a placebo for 2 weeks. Upper extremity function was assessed at baseline, after 1 week, after 2 weeks of treatment, and 2 weeks post-treatment using clinical tests (9-Hole Peg Test, Box, and Block Test, peak isometric grip force, 2-point discrimination) and self-reported questionnaires (disabilities of the arm, shoulder and hand, ability measure of the hand, Manual Ability Measurement 36). Data were analyzed using repeated-measures analysis of variance to evaluate group × time interactions.

Results

No significant group × time interactions were observed across clinical or self-reported outcomes. Both groups exhibited similar trends over time, with no measurable improvements in upper extremity dexterity, strength, or perceived function attributable to dalfampridine.

Conclusion

Sustained-release dalfampridine does not appear to improve upper extremity function in pwMS, highlighting its limitations beyond gait-related benefits. These findings underscore the need for further research to explore alternative treatments targeting upper limb dysfunction in this population.

Trial registration

ClinicalTrials.gov NCT02259361.

Weak grip strength among persons with multiple sclerosis having minimal disability is not related to agility or integrity of the corticospinal tract

INTRODUCTION

Mobility impairment is common in multiple sclerosis (MS); however, agility has received less attention. Agility requires strength and neuromuscular coordination to elicit controlled propulsive rapid whole-body movement. Grip strength is a common method to assess whole body force production, but also reflects neuromuscular integrity and global brain health. Impaired agility may be linked to loss of neuromuscular integrity (reflected by grip strength or corticospinal excitability).

OBJECTIVES

We aimed to determine whether grip strength would be associated with agility and transcranial magnetic stimulation (TMS)-based indices of corticospinal excitability and inhibition in persons with MS having low disability. We hypothesized that low grip strength would predict impaired agility and reflect low corticospinal excitability.

METHODS

We recruited 34 persons with relapsing MS (27 females; median [range] age 45.5 [21.0-65.0] years) and mild disability (median [range] Expanded Disability Status Scale 2.0 [0-3.0]), as well as a convenience sample of age- and sex-matched apparently healthy controls. Agility was tested by measuring hop length during bipedal hopping on an instrumented walkway. Grip strength was measured using a calibrated dynamometer. Corticospinal excitability and inhibition were examined using TMS-based motor evoked potential (MEP) and corticospinal silent period (CSP) recruitment curves, respectively.

RESULTS

MS participants had significantly lower grip strength than controls independent of sex. Females with and without MS had weaker grip strength than males. There were no statistically significant sex or group differences in agility. After controlling for sex, weaker grip strength was associated with shorter hop length in controls only (r = 0.645, p < .05). Grip strength did not significantly predict agility in persons with MS, nor was grip strength predicted by corticospinal excitability or inhibition.

CONCLUSIONS

In persons with MS having low disability, grip strength (normalized to body mass) was reduced despite having intact agility and walking performance. Grip strength was not associated with corticospinal excitability or inhibition, suggesting peripheral neuromuscular function, low physical activity or fitness, or other psychosocial factors may be related to weakness. Low grip strength is a putative indicator of early neuromuscular aging in persons with MS having mild disability and normal mobility.

Fampridine in multiple sclerosis patients with acute phase of cervical transverse myelitis: a double-blind, randomized placebo-controlled trial

BACKGROUND

Fampridine is a potassium channel blocker drug used to improve walking ability in patients with multiple sclerosis (MS). We evaluated the effect of fampridine in patients with MS in the acute phase of transverse myelitis.

METHODS

In a randomized, placebo-controlled trial, 30 patients who had their first episode of cervical myelitis with quadriparesis presentation, with the final diagnosis of MS, were randomly divided into two equal groups. The intervention group received intravenous methylprednisolone (IVMP) for 7 days plus fampridine. The placebo group received IVMP for 7 days plus placebo. To compare the treatment results, we compared the Barthel index (BI) scores of the groups at the start of the trial and the 21st day after the start of treatment.

RESULTS

There was no significant difference in baseline characteristics between the intervention and placebo groups in terms of mean age, sex, and mean admission BI (p > 0.05). Mean (SD) admission BI in placebo and intervention groups was 27.20 (7.341) and 27.87(5.78), respectively (p = 0.784). The measured mean (SD) BI after treatment was 48.73 (15.54) in the placebo and 64.93 (11.81) in the intervention group (p = 0.003) after 3 weeks.

CONCLUSION

Using fampridine plus IVMP in the acute phase of transverse myelitis in MS patients improved the disease's symptoms and increased the daily activity ability of patients.

The Use of Motor-Evoked Potentials in Clinical Trials in Multiple Sclerosis

SUMMARY

Motor-evoked potentials (MEPs) can be used to assess the integrity of the descending corticospinal tract in the laboratory. Evoked potentials (EPs) have been widely used in the past for the diagnosis of multiple sclerosis (MS), but they are now becoming more useful in assessing the prognosis of the disease. Motor-evoked potentials have been included in EP scales that have demonstrated good correlations with clinical disability. Soon after the onset of MS, it is possible to detect an ongoing process of neurodegeneration and axonal loss. Axonal loss is probably responsible for the disability and disease progression that occurs in MS. Given the good correlations of EPs in detecting disease progression in MS, they have been used to monitor the effects of drugs used to treat the disease. Several clinical trials used MEPs as part of their EP evaluation, but MEPs have never been used as a measure of efficacy in clinical trials testing neuroprotective agents, although MEPs could be a very promising tool to measure neuroprotection and remyelination resulting from these drugs. To be used in multicenter clinical trials, MEP readings should be comparable between centers. Standardized multicenter EP assessment with central reading has been demonstrated to be feasible and reliable. Although MEP measurements have been correlated with clinical scores and other measures of neurodegeneration, further validation of MEP amplitude measurements is needed regarding their validity, reliability, and sensitivity before they can be routinely used in clinical drug trials in MS.

Dalfampridine in the treatment of multiple sclerosis: a meta-analysis of randomised controlled trials

Background

Multiple sclerosis (MS) is a chronic illness involving the central nervous system (CNS) that is characterised by inflammation, demyelination, and degenerative changes. Dalfampridine is one of the available treatments for MS symptoms and comorbidities. This meta-analysis aimed to assess the safety and benefits of dalfampridine versus placebo in MS by summarising data deriving from previously published clinical randomised controlled studies (RCTs).

Results

A total of 9 RCTs were included in this meta-analysis, involving 1691 participants. There were significant differences between dalfampridine and placebo in terms of decreased 12-item Multiple Sclerosis Walking Scale score (weighted mean difference [WMD] =  − 3.68, 95% confidence interval [CI] [− 5.55, − 1.80], p = 0.0001), improved response to the timed 25-foot walk test (relative risk [RR] = 2.57, 95% CI [1.04, 6.33], p = 0.04), increased 6-min walk test (WMD = 18.40, 95% CI [1.30, 35.51], p = 0.03), increased 9-Hole Peg Test score (WMD = 1.33, 95% CI [0.60, 2.05], p = 0.0004), and increased Symbol Digit Modalities Test score (WMD = 4.47, 95% CI [3.91, 5.02], p < 0.00001). Significant differences in the incidence of side effects were also observed (RR = 1.12, 95% CI [1.04, 1.21], p = 0.002).

Conclusion

Dalfampridine exerts positive effects on walking ability, finger dexterity, and cognitive function. Treatment should be administered under the guidance of a physician or pharmacist given the higher incidence of adverse events.

Aminopiridines in the treatment of multiple sclerosis and other neurological disorders

Symptomatic treatment has a great relevance for the management of patients with neurologic diseases, since it reduces disease burden and improves quality of life. Aminopyridines (APs) are a group of potassium (K+) channel blocking agents that exert their activity both at central nervous system level and on neuromuscular junction. This review describes the use of APs for the symptomatic treatment of neurological conditions. We will describe trials leading to the approval of the extended-release 4-aminopyridine for MS and evidence in support of the use in other neurological diseases.

The Potential Role of Neurophysiology in the Management of Multiple Sclerosis-Related Fatigue

Fatigue is a very common symptom among people with multiple sclerosis (MS), but its management in clinical practice is limited by the lack of clear evidence about the pathogenic mechanisms, objective tools for diagnosis, and effective pharmacological treatments. In this scenario, neurophysiology could play a decisive role, thanks to its ability to provide objective measures and to explore the peripheral and the central structures of the nervous system. We hereby review and discuss current evidence about the potential role of neurophysiology in the management of MS-related fatigue. In the first part, we describe the use of neurophysiological techniques for exploring the pathogenic mechanisms of fatigue. In the second part, we review the potential application of neurophysiology for monitoring the response to pharmacological therapies. Finally, we show data about the therapeutic implications of neurophysiological techniques based on non-invasive brain stimulation.